Using Python 3+ write the following functions and provide a program to test them. Provide comments inside of the code. DO NOT USE THE min() FUNCTION, create your own function. Show a UNIT tests in main(). You will not have the user input value, instead you will be doing a UNIT test (on the two functions) inside the main().

def smallest (x, y, z) (returning the smallest value of the arguments0

def average (x, y, z) (returning the average of the arguments)